JERUSALEM, Aug 5 (Reuters) - Israel has deployed a new interceptor missile battery to the coastal town of Ashkelon following the latest barrage of rockets that militants fired from the Gaza Strip over the past two days, the military said on Friday.

Israel responded with air strikes at Gaza targets after militants launched military-grade Grad rockets on Wednesday and Thursday that landed in several areas in Israel up to 40km (25 miles) north of the coastal strip, the military said.

Gaza medical officials said three Palestinian civilians were wounded from an air strike in the northern part of the coastal enclave at dawn on Friday, two of them were in serious condition.

On Thursday, Israeli aircraft bombed two training camps belonging to the Islamist Hamas faction that controls the territory and did not cause injuries, witnesses said.

Hamas say the rockets are fired by some militants who refuse to heed an agreement among the major Gaza factions, led by Hamas, to hold fire against Israel.

The Israeli military says that since the start of 2011 over 340 rockets and mortar shells have been fired at the Jewish state from the Gaza Strip.

Israel's new Iron Dome system was rolled out in March after rushed production to counter the rockets fired by Gaza militants. It only intercepts rockets that it calculates will hit built-up areas and ignores those set to land in open areas.

The system won plaudits from U.S. National Security Adviser Tom Donilon for downing eight out of nine Katyusha-style rockets launched at two southern Israeli cities over the course of a day earlier this year. (Additional reporting by Nidal al-Mughrabi in Gaza, writing by Ori Lewis)